Scanner with retractable roller feed

Abstract

A scanner is operative with an imaging system for inducing a mechanical movement of a subject during an optical scanning of the subject to provide an image of the subject. The subject which is in the shape of a card is advanced along a travel path past an optical viewing site by means of a drum, the scanner including a first roller and a second roller which urge the subject against the drum. Initially, the first roller is located between the viewing site and the entry port for receipt of the subject in a first nip between the first roller and the drum. The second roller is positioned fixed on the opposite side of the viewing site. The first roller is supported by an arm which swings about a rotational axis of the drum to vary the spacing between the two rollers. Upon rotation of the drum in a forward direction for induction of the subject, a brake located between the drum and the arm drags the arm and the first roller towards the second roller to facilitate a transference of a leading edge of the subject from the first nip to a second nip defined by the second roller and the drum. Preparatory to optical scanning of the subject which is accomplished during reverse rotation of the drum, the arm swings the first roller away from the second roller to present the viewing site to the optical scanning beam.

What is claimed is: 
     
       1. A scanner operative to move a subject past a light beam comprising: a drum disposed in an optical path of the light beam;   a first roller and a second roller, both of said rollers being in contact with a cylindrical surface of said drum and lying along a path of travel of the subject, rotation of said drum moving the subject along said travel path, said first roller and said drum defining a first nip for receiving the subject upon insertion of the subject into the scanner, there being a spacing between the axes of said rollers which is variable from a first distance to a second distance, said first distance being substantially less than said second distance, the second distance defining a viewing site between said rollers for receipt of the light beam; and   means for varying said axial spacing between said rollers, said spacing being decreased to said first distance for transference of a leading edge of the subject from said first nip to a second nip defined by said second roller and said drum, said spacing being increased to said second distance upon a scanning of the subject with the light beam.   
     
     
       2. A scanner according to claim 1 wherein said drum rotates in a forward direction preparatory to said scanning, said drum rotating in a reverse direction during said scanning, a portion of said subject being retained within said first nip during movement of the subject along said travel path. 
     
     
       3. A scanner according to claim 2 wherein said varying means comprises: a swing arm extending radially outward of a rotational axis of said drum and having an inner end pivotally connected about said drum axis;   means for connecting said first roller to an outer end of said arm opposite said inner end of said arm; and   brake means interconnecting said arm to said drum for producing a torque upon said arm during rotation of said drum, the torque inducing a swinging of said arm and said first roller about said drum.   
     
     
       4. A scanner according to claim 3 further comprising a shaft for supporting said first roller, said first roller being rotatable about said shaft; and wherein in said varying means, said connecting means includes a spring-loaded strut extending from said shaft of said first roller to said outer end of said swing arm, said strut being pivoted to said arm for urging said first roller toward said drum.   
     
     
       5. A scanner according to claim 4 wherein said varying means comprises means for stopping a swing of said arm at an outer stop point along said travel path and an inner stop point along said travel path, said outer stop point being located between said viewing site and an entry port of the scanner wherein the subject is inserted into the scanner, said inner stop point being located between said outer stop point and said second roller. 
     
     
       6. A scanner according to claim 3 wherein said varying means comprises means for stopping a swing of said arm at an outer stop point along said travel path and an inner stop point along said travel path, said outer stop point being located between said viewing site and an entry port of the scanner wherein the subject is inserted into the scanner, said inner stop point being located between said outer stop point and said second roller. 
     
     
       7. A scanner according to claim 6 further comprising an outer sensor and an inner sensor of the presence of the subject on said travel path, said outer sensor sensing the presence of the subject at an outer travel point located between said outer stop point and said entry port, said inner sensor sensing the presence of the subject at an inner travel point located on a side of said second roller opposite said entry port; and   computer means operative to direct rotation of said drum in the forward direction and in the reverse direction, said computer means being responsive to signals of said outer sensor and said inner sensor to determine a length of said subject measured along said travel path and wherein, upon activation of said computer means subsequent to an insertion of the subject into the scanner, said computer means directs rotation of said drum in the forward direction to bring a trailing edge of the subject into said first nip with said swing arm being at said inner stop point, said computer means then directing a rotation of said drum in the reverse direction to bring said leading edge into said first nip with said swing arm at the position of said outer stop point.   
     
     
       8. A scanner according to claim 3 further comprising means for holding said second roller fixed in position during a movement of said first roller upon a swinging of said arm.